This invention related to uniform loading springs traditionally included in a category of springs described generally as leaf springs, diaphragm springs, suspension springs or the like that form a cushioning or load bearing function. The springs of this invention may be employed in a wide variety of systems and can replace existing washers and springs such as wavy spring washers, curved spring washers, compression springs, and precision washers as well as lockwashers and the springs noted above. The springs comprising the present invention are controlled by simple beam deflection.
Prior art devices bearing some similarity to the present invention are reflected in, for example, U.S. Pat. No. 2,179,575 to Hosking, entitled "Lock Washer." This patent describes a device having a plurality of projections or locking elements which project from opposite sides of the washer body. In such a structure, these projections may include corners or edges that define sharp work-engaging corners or edges that can embed themselves within the surface of the work piece; i.e. a screw head or nut. Thus, Hosking encourages the lock washer to engage the adjacent member--the underside of a screw head or a nut--in a scraping or scarring manner, so as "to effectively secure the nut against retrograde movement."
Consequently, an object of this invention is to provide springs which have great versatility; uniform spring loading, compression, and flexibility under variable environmental conditions; and no damage to adjacent members. The springs of the present invention are designed to minimize friction, overheating, shear, stress, fatigue, deformation, noise levels, oscillations, and vibrations. Another object is to reduce weight and bulk and enhance load capacity as compared to existing springs employed for comparable jobs.
Existing lockwashers are typically loaded at one or sometimes several points. This causes shearing, scarring or other damage to the screw or base of the metal. However, if washers are used on both sides of the ordinary lockwasher, there is a tendency to loosen under vibration. Thus, another object of this invention is to prevent such spring loosening because of spring tension while avoiding metal fracture, scarring and chipping.
Many spring systems and designs have failed because of lack of uniform loading and maintenance of alignment in many areas (bearings and optical precision instruments, for example) due to temperature changes, stress, humidity, atmospheric pressure and other environmental factors that may cause critical variations. In bearing designs, proper alignment and adjustment of the ball track is very important to prevent skidding and noise and to increase bearing life. In optical and other precision instruments (such as those employed in outerspace), maintaining uniform loading, providing for expansion and contraction, reducing stress, preventing deformation, and damping of vibrations or oscillations are vital to proper and successful performance.
Presently available wavy washers cannot be fabricated for sensitive uniform loading because of their configuration. The wavy portion on each contact segment is not equal and has a different spring rate. Twisting taking place on each contact segment causes undue stress which does not permit the material to return to its original position. This results from structural fatigue. Belleville spring washers have similar problems because of buckling. Deformation or fracture of the spring can destroy the entire system in which it is employed.
It was to overcome these and other disadvantages of the prior art that the present invention was developed.